JP2002051586A - Boring device and boring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To see that reinforcement such as reinforcing rods buried in a substance to be excavated does not break during boring, by boring the substance to be bored, in a short time. SOLUTION: A boring device is composed of a core bit 13 which has a bit to bore concrete C being substance to be excavated at the tip, a rotary shaft 11 where the core bit 13 is attached to the tip, a direct motor 2 which is equipped with a rotor 17 being provided integrally with this rotary shaft 11 passed thereinto, and a power source 1b which applies voltage to the direct motor 2. The direct motor 2 is a DC motor which rotates, being impressed with DC voltage, and the power source 1b is provided with a current detector which detects the current flowing to the motor, and a motor drive voltage stopping means which stops the output of the DC voltage to the motor when the current value detected by that current detector gets over a threshold.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for embedding a post-installed anchor or the like in a concrete structure. When a tool comes into contact with a reinforcing body such as a reinforcing bar that reinforces a concrete structure,
The present invention relates to a drilling device and a drilling method for stopping drilling to prevent breakage of a reinforcement.

[0002]

2. Description of the Related Art As a method of reinforcing an existing concrete wall, first, the wall is largely pierced, an iron brace is provided in the opening, and then the brace and the opening are formed. There is a method of reinforcing the entire wall by solidifying an anchor provided on the inner peripheral surface with concrete. At this time, the anchor is disposed by being housed in a hole provided on the inner peripheral surface of the opening. As shown in FIG. 4, a hole for disposing the anchor is a core bit 80 (tool) having an annular bit 80a made of diamond, a carbide tip or the like at the tip of a cylindrical member.
And a motor 81 for rotating the core bit 80 around the axis. That is, the core bit 8 is placed on the concrete 82 to be excavated.
The concrete 82 is perforated by rotating and pressing the bit 80 a provided at the leading end of the “0” to form a cylindrical core 83. Then, by breaking the root 83a of the core core 83 remaining inside the concrete 82 and then pulling out the core core 83, for example, a diameter of 20 to 35
A hole for arranging an anchor having a depth of about 200 mm and a depth of about 200 mm is formed.

[0003]

By the way, in order to increase the generated torque obtained under a predetermined output power, the above-mentioned motor 81 rotates the rotating shaft on which the core bit 80 is mounted by a gear or the like as shown in the figure. The number is reduced to drive. For this reason, like an engine or a hydraulic motor, the weight becomes heavy, the handling is lacking, and further,
Due to friction in a rotation transmission mechanism such as a gear, there has been a problem that the torque obtained by the rotation shaft decreases and the noise is large. Further, lowering the rotation speed under a predetermined drilling speed increases the drilling depth per tool rotation, in other words, the drilling depth of the bit to be drilled, and increases resistance to drilling. Means that. Eventually, the increase in the resistance to the excavation exceeds the increase in the generated torque of the motor, which actually lowers the drilling speed and lengthens the drilling time. In addition, noise and vibration during drilling are increased due to increased resistance to excavation, and construction is prolonged due to extension of drilling time, which has been an environmental problem for surroundings during construction. Further, since the torque of the tool during excavation increases, there is a possibility that the reinforcing body may be cut as it is even when it comes into contact with a hard reinforcing body such as a reinforcing bar in concrete. In the construction for the purpose of reinforcing the building, if the existing reinforcing body is damaged, the construction itself is meaningless, and the development of appropriate technology to prevent such a problem is desired. I was

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a drilling device and a drilling device capable of preventing a reinforcing body such as a reinforcing bar buried in an excavated object such as concrete from being damaged during drilling. It is intended to provide a drilling method. Another object is to provide a drilling device and a drilling method capable of drilling an excavated object in a short time.

[0005]

According to the first aspect of the present invention, there is provided a tool having a bit at a tip end for drilling an object to be excavated;
A motor that rotationally drives the tool, and a drilling device including a motor power supply that applies a voltage to the motor, wherein the motor is a DC motor that rotates when a DC voltage is applied, and the motor power supply includes: A current detector for detecting a current flowing through the motor, and motor drive voltage stopping means for stopping output of the DC voltage to the motor when a current value detected by the current detector exceeds a threshold value. It is characterized by doing.

In the present invention, when a bit for piercing an object to be excavated comes into contact with a hard reinforcing member in the object to be excavated, the number of rotations is reduced or the rotation is completely stopped. The current flowing to the motor increases. This increased current value is detected by a current detector provided in the motor power supply, and when this value exceeds a threshold value, the motor drive voltage stopping means sets the voltage applied to the motor to zero. In this way, when the bit comes into contact with the reinforcing member, the output of the voltage from the motor power supply stops, the rotation of the bit stops completely, the damage to the reinforcing member is prevented, and an excessive current flows through the motor, causing the motor to generate heat. However, it is possible to prevent the winding from being short-circuited due to breakage of the insulating film.

According to a second aspect of the present invention, there is provided the drilling apparatus according to the first aspect, wherein the motor power supply adjusts a firing angle of a trigger current to be applied to a gate of the triac to thereby control an AC voltage on the input side. A phase control unit that periodically outputs a part of the phase, and a rectification unit that rectifies the voltage on the output side of the phase control unit so as to apply the DC voltage to the motor and smoothes voltage pulsation. The motor drive voltage stopping means is configured to adjust the firing angle when the current value exceeds a threshold value to stop outputting a voltage to the rectifier.

In the present invention, the phase control section of the motor power supply is configured to have a triac, and periodically outputs only a part of the phase of the AC voltage on the input side. That is, a trigger current to be applied to the gate of the triac is generated using, for example, a diac or the like, and a timing (ignition angle) at which the trigger current is applied is adjusted to select a phase at which the AC voltage is output. That is, an output is obtained in which a part of the peak of the AC voltage on the input side that draws a sine curve is cut off. If this output is smoothed in the rectifier, the average output voltage decreases. For example, when the firing angle is set to 180 °, no voltage is output to the rectifier. Thus, by adjusting the firing angle of the trigger current applied to the triac gate, the voltage value applied to the motor can be adjusted. The current flowing through the motor is detected by a current detector, and as soon as the current value exceeds a threshold value, the firing angle is set to 180 ° by motor drive voltage stopping means having a control circuit to stop applying voltage to the motor. In this way, when the bit comes into contact with the reinforcing member, the output of the motor power supply is stopped, the rotation of the bit stops completely, preventing damage to the reinforcing member, and causing excessive current to flow through the motor, causing the motor to generate heat and insulation. It is possible to prevent the winding from being short-circuited due to breakage of the film.

According to a third aspect of the present invention, there is provided the drilling apparatus according to the second aspect, wherein the rectifying unit has a capacitor connected in parallel with the motor.

In the present invention, the rectifying unit includes, for example, a diode bridge assembled for full-wave rectification, and a capacitor connected in parallel to the motor. Increasing the capacity of the capacitor is not only effective in removing the ripple of the voltage applied to the motor and stabilizing the voltage, but also flows instantaneously when the bit stops against the reinforcement. The capacitor plays a role as a buffer for the charge that supplies the surge current. In this way, it is possible to prevent an excessive current from flowing to the motor power supply instantaneously.

According to a fourth aspect of the present invention, there is provided the drilling apparatus according to any one of the first to third aspects, wherein the rotary shaft through which the tool is attached is penetrated at a tip end of the motor. And a cylindrical rotor provided on the outer peripheral surface of the rotor.

In the present invention, the rotary shaft on which the tool is mounted is provided integrally with the rotor of the motor, and is directly driven to rotate without the intervention of gears or the like. Therefore, the torque generated by the motor can be directly used for excavation without being lost by friction of the rotation transmission mechanism or the like. Also, weight and noise can be reduced. With such a configuration, the rotation speed of the tool becomes the rotation speed obtained by the motor as it is, and the bit can be rotated at high speed. Increasing the number of revolutions at a given drilling speed is equivalent to the drilling depth per tool revolution,
In other words, it means that the depth of excavation of the bit into the object to be excavated is reduced, and the resistance to excavation is reduced.
The amount of decrease in the resistance to excavation exceeds the amount of decrease in the torque generated by the motor, thereby enabling an increase in the drilling speed and a reduction in the drilling time. In this way, the drilling speed can be increased as compared with the case where the number of revolutions is reduced by using a gear or the like.

According to a fifth aspect of the present invention, there is provided the drilling apparatus according to the fourth aspect, wherein the tool having the bit at its tip and the rotary shaft are both provided in a cylindrical shape, and the tool is It is characterized in that it is attached to the rotating shaft and communicates with each other in the axial direction.

With this configuration, not only water can be passed from the rotary shaft to the bit at the tip of the tool for wet excavation, but also the core core remaining in the concrete after drilling the concrete passes through the rotary shaft. It is also possible to extract or insert an extruding rod, for example, to extrude the core. Also, various configurations for cooling can be provided in the rotating shaft. For example, cooling may be performed by passing cooling water, providing a fan for air cooling, passing liquid nitrogen or dry ice, or adiabatically expanding a compressed gas. In particular, since the rotating shaft is directly attached to the rotor of the motor and provided integrally with the rotor, the heat conductivity to the motor is good, and the motor can be efficiently cooled.

According to a sixth aspect of the present invention, there is provided the drilling apparatus according to any one of the third to fifth aspects, wherein the triac has a withstand current value of at least 40 A, and the capacitor has a capacity of at least 15000 μF. It is characterized by having.

[0016] With this configuration, the bit abuts against a reinforcing member such as a reinforcing bar in the concrete during drilling and stops, and even if an excessive current flows to the motor, the capacity of the capacitor supplies a surge current. However, an excessive current can be prevented from flowing instantaneously to the motor power supply. Further, the triac also has a sufficient current resistance, and can be prevented from being broken.

According to a seventh aspect of the present invention, there is provided the punching apparatus according to any one of the first to sixth aspects, wherein a winding in the motor is covered with a heat-resistant resin. I do.

[0018] With this configuration, the bit contacts the hard excavated object, the rotation speed of the motor decreases, and a large amount of current determined only by the winding resistance flows along with the reduction of the induced voltage and the Joule heat is generated. Does not occur, there is no short circuit between the windings.

The invention according to claim 8 is the drilling device according to any one of claims 1 to 7, wherein the tool having the bit and the motor are separate from the motor power supply. The punching device main body is provided on the body, and the punching device main body is provided with a reset button for releasing the stop of the output of the DC voltage to the motor.

With this configuration, even if a current greater than the threshold value flows through the motor and the voltage applied to the motor drops, the work can be resumed with the reset button at hand after the problem is solved. The performance is improved.

According to a ninth aspect of the present invention, a tool having a bit is mounted on a rotating shaft driven to rotate by a motor, and a DC voltage is applied to the motor from a motor power supply to rotate and rotate the motor. A drilling method for piercing the excavated object by pressing the bit against the excavated object, wherein the bit abuts on a reinforcing body for reinforcing the excavated object embedded in the excavated object. It is characterized in that an increase in a current value flowing through the motor is detected, and the motor is stopped when the detected current value exceeds a threshold value.

In the present invention, when the bit for piercing the object to be excavated comes into contact with a hard reinforcing member in the object to be excavated, the rotation speed is reduced or the rotation is completely stopped. The current flowing to the motor increases. When this increased current value is detected and a value exceeding the threshold value is detected, the voltage applied to the motor is immediately reduced to zero. Thus,
When the bit comes into contact with the reinforcing member, the output of the motor power supply stops, the rotation of the bit stops completely, preventing damage to the reinforcing member, and causing an excessive current to flow through the motor, causing the motor to generate heat and causing the insulating film to form. It is possible to prevent the winding from being short-circuited due to breakage.

According to a tenth aspect of the present invention, the rotary shaft is directly attached to a rotor that rotates a motor, and a tool having a bit at a tip is attached to the rotary shaft to rotate the motor and rotate the motor. A drilling method for drilling the excavated object by pressing a bit against the excavated object,
The resistance to digging and the torque required for digging are increased by increasing the total number of revolutions of the tool required to drill a given depth and reducing the depth of digging per revolution of the bit into the digging object. Reducing the total work required for drilling the predetermined depth and increasing the drilling speed for drilling the excavated object.

In the present invention, the total number of revolutions of the tool required for drilling a predetermined depth is increased, the total work required for drilling a predetermined depth is reduced, and the drilling speed for drilling an excavated object is reduced. increase. The total work required to drill a given depth is, as it were, the product of the force applied to the bit at the tool tip and the total travel distance of the bit. Increasing the total number of revolutions of the tool required to drill a given depth will certainly increase the total mileage of the bit, but will reduce the depth of drilling per revolution of the bit to And the torque required for excavation is reduced, and the overall work required to drill a given depth as a whole can be reduced. The time required for drilling is equivalent to a value obtained by dividing the total work required for drilling a predetermined depth by the output of the motor in an ideal case in which torque transmission loss and the like are not taken into consideration. By reducing the total work required to drill a predetermined depth, the time required to drill a predetermined depth is reduced. That is, the drilling speed increases.
For example, let the rotation speed of the tool be the rotation speed obtained by the motor,
The bit is rotated at a high speed, and the rotation speed is increased under a predetermined drilling speed. Then, the drilling depth per tool rotation, in other words, the depth of excavation of the bit into the excavated object becomes smaller,
Resistance to excavation can be reduced. The amount of decrease in the resistance to excavation exceeds the amount of decrease in the torque generated by the motor, so that the drilling speed can be increased and the drilling time can be shortened. Thus, the perforation time can be reduced as compared with a case where the number of revolutions is reduced by using a gear or the like.

According to an eleventh aspect of the present invention, there is provided the drilling method according to the tenth aspect, wherein the bit comes into contact with a reinforcing member for reinforcing the excavated object buried in the excavated object. Detecting an increase in the value of current flowing through the motor,
When the detected current value exceeds a threshold value, the motor is stopped.

In the present invention, the drilling speed is increased, and drilling is performed so as not to drill the reinforcing body of the drilling object buried in the drilling object. When the bit for piercing the excavated object comes into contact with the hard reinforcing member in the excavated object, the rotation speed decreases or stops completely, and the current flowing through the motor increases as the induced voltage of the motor decreases. When this increased current value is detected and a value exceeding the threshold value is detected, the voltage applied to the motor is immediately reduced to zero. Thus,
When the bit comes into contact with the reinforcing member, the output of the motor power supply stops, the rotation of the bit stops completely, preventing damage to the reinforcing member, and causing an excessive current to flow through the motor, causing the motor to generate heat and causing the insulating film to form. It is possible to prevent the winding from being short-circuited due to breakage.

According to a twelfth aspect of the present invention, there is provided the drilling method according to any one of the ninth and eleventh aspects, wherein a reinforcing body for reinforcing the excavated object buried in the excavated object is provided. An input is detected by detecting an increase in the value of the current flowing through the motor due to the contact of the bit, and adjusting the firing angle of the trigger current to be applied to the triac gate when the detected current value exceeds a threshold value. The application of the DC voltage to the motor is stopped by stopping the output of the AC voltage on the side.

In the present invention, the current flowing through the motor is detected, and when the current value exceeds the threshold value, the firing angle of the trigger current applied to the triac gate is set to 180 immediately.
Adjust to ° and stop applying voltage to the motor.

According to a thirteenth aspect of the present invention, there is provided the drilling method according to the thirteenth aspect, wherein the triac has a withstand current value of at least 40 A, and the capacitor has at least a capacitance of 15000 μF. Features.

In the present invention, even when the bit abuts against a reinforcing member such as a reinforcing bar in the concrete during drilling and stops, even if an excessive current flows to the motor, the capacity of the capacitor supplies a surge current and the motor power Instantaneous excessive current flow can be prevented. Further, the triac also has a sufficient current resistance, and can be prevented from being broken.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a punching device and a drilling method according to the present invention will be described with reference to the drawings. 1 to 3, reference numeral 1 denotes a punching device, reference numeral 1a denotes a punching device main body,
Reference numeral 1b denotes a power supply (motor power supply), and reference numeral 2 denotes a motor (hereinafter, referred to as a direct motor) of the present embodiment, which constitutes the punching device main body 1a driven by the power supply 1b. The punching device main body 1a has a structure in which the direct motor 2 is supported on a column 4 erected on a base 3 via a vertical mechanism 5, and the direct motor 2 is moved along the column 4 by the vertical mechanism 5. To be moved.

The direct motor 2 is a DC motor that rotates when a DC voltage is applied thereto. The direct motor 2 has a cylindrical rotating shaft 11 at the center thereof.
Cylindrical core bit 13 (tool) via adapter 12
Are detachably attached so as to communicate with the rotating shaft 11.

Here, the core bit 13 has a structure in which a bit 15 made of a diamond bit is integrally provided in a circumferential direction at a distal end portion of a tube 14 formed in a hollow shape. That is, the core bit 13 is provided with a bit 15 made of a hard metal or a diamond tool obtained by hardening super abrasive grains (diamond abrasive grains or CBN abrasive grains) with a binder such as a metal bond or a resin bond at the tip of the tube 14. ing. The concrete C is excavated by rotating the core bit 13 to form a columnar core. Here, as the core bit 13, for example, when a direct motor 2 having an output of about 800 W is used,
Outer diameter 40mm or less can be used, outer diameter 15-30m
m is preferred. Also, as the blade thickness of the bit 15,
Less than 2.0 mm can be used, with 1.8 mm being preferred.

As described above, the direct motor 2 is a direct type motor that directly rotates the core bit 13 which is a tool directly connected to the rotating shaft 11 without using a rotation transmission mechanism such as a gear. The direct motor 2 includes a rotor 17 in which a coil coated with a heat-resistant resin such as polyimide is wound inside a housing 16,
7 and a cylindrical stator 18 having a permanent magnet. The rotating shaft 11 is
The rotor 17 is inserted so as to be pressed into an insertion hole 17 a formed at the center of the rotor 17 and is integrally fixed to the rotor 17. Bearings 19a and 19b for rotatably supporting the rotor 12 are provided inside the upper wall portion 16a and the lower wall portion 16b of the housing 16, respectively.
That is, the bearings 19a and 19b support the vicinity of the upper and lower ends of the rotating shaft 11 inserted into the center of the rotor 17, and act on the rotating shaft 11 and the rotor 17 through which the rotating shaft 11 is inserted. It is configured to be able to receive a thrust force and a radial force.

A rotary joint 21 is provided at the rear end of the direct motor 2. The rotary joint 21 is connected to the upper wall 16 a of the housing 16.
And is rotatably connected to the rear end of the rotating shaft 11 in a liquid-tight manner. The rotary joint 21 is formed with a flow path 22 communicating with the through hole 11 a at the center of the rotary shaft 11, and the flow path 22 is opened to the side of the rotary joint 21. A tube 24 is connected to the opening 23 opened to the side, and cooling water for wet excavation is sent from the tube 24. And, from this tube 24, the rotary joint 21
Through the passage 22 of the rotary shaft 11, and then fed into the core bit 13 connected to the tip of the rotary shaft 11 via the adapter 12, and
5 is cooled. The rotary joint 21 has a mounting screw portion 31 formed at a rear end thereof, and a cap 32 is screwed into the mounting screw portion 31 and fixed. The cap 32 has an insertion hole 34 formed at its center. In addition, rotary joint 2
1 has a communication hole 35 communicating with the insertion hole 34 of the cap 32 and the through hole 11a of the rotating shaft 11. An extruding rod 36 is inserted into the through-hole 34, the through-hole 35 and the through-hole 11a which communicate with each other. An O-ring 37 is provided between the push rod 36 and the insertion hole 34 of the cap 32 to be sealed.

Reference numeral 25 denotes a brush portion disposed in the circumferential direction on the upper side in the housing 16 of the direct motor 2 so as to contact the rotary shaft 11. And a drive current is supplied.

The magnet of the stator 18 is a neodymium-iron-boron-based or samarium-cobalt-based rare earth element having a much higher maximum magnetic energy product than a commonly used ferrite magnet or alnico magnet. Is used.

The direct motor 2 having the rotor 17 and the stator 18 may be a brush motor or a brushless motor. In the above example, a magnet is provided on the stator 18 side and a coil is provided on the rotor 17 side. However, a coil may be provided on the stator 18 side and a magnet may be provided on the rotor 17 side, or both may be provided as coils.

A motor power supply 1b for supplying a DC voltage to the direct motor 2 is roughly composed of a power supply main body 5, a control section 5a provided on the side of the punching apparatus main body 1a, and a cable 5b for electrically connecting these. ing. As shown in FIG. 1, the power supply body 5 includes an input cable 52 having a plug 51 for introducing an AC voltage supplied to a work site into the power supply body 5. In addition to the main switch 53, the power supply main body 5 is provided with a current amount selection switch 54 that can appropriately select a current amount according to the allowable current amount of the power supply on the input side. Although not shown here, the power supply body 5
In addition to the above, a switch for emergency stop of the drilling operation, a cooling water inlet for introducing cooling water for power supply cooling, and the like are provided. The control unit 5a has a rotation speed adjusting knob 55a for adjusting the rotation speed of the direct motor 2, a start and stop of the rotation of the direct motor 2 at hand, and an output voltage dropped to zero due to a power supply interlock. A reset button 55b is provided to restart the rotation again in the case.

FIG. 3 is a block diagram schematically showing an electric circuit configuration of the punching device 1. As shown in FIG. 3, the power supply 1b periodically outputs a part of the phase of the AC voltage on the input side T1 to the output side T2 by adjusting the firing angle of the trigger current applied to the gate G of the triac T. A phase control unit 56 and a rectifying unit 57 for rectifying the voltage on the output side T2 of the phase control unit 56 so as to apply a DC voltage to the direct motor 2 and smoothing the voltage pulsation.

The phase control unit 56 has a triac control unit 58 for applying a trigger current from, for example, a diac to the gate G of the triac T.
The firing angle of the trigger current is adjusted as appropriate based on an input (indicated by VAL in the drawing) from a current amount selection switch 54 provided on the side and an input (indicated by RES in the drawing) from a reset button 55, and output. It is configured to control the output to the side T2. Further, the power supply 1b includes a current detector 59 for detecting a current flowing through the direct motor 2, and when the current value detected by the current detector 59 exceeds a threshold value, the triac control unit 58 immediately activates the ignition angle. The motor drive voltage stopping means is configured to stop the output of the voltage to the rectifier 57 by adjusting the voltage.

The rectifying section 57 is electrically connected in parallel with the direct motor 2 to the diode section 57a for full-wave rectifying the output voltage of the phase control section 56 in which a part of a sine curve is cut off. And a capacitor 57b for rectifying the voltage and smoothing the voltage pulsation. Further, the rectifying section 57 is provided with a circuit (not shown) for quickly discharging the stored electric charge from the capacitor 57b when the direct motor 2 stops, and the stored electric charge causes the direct motor 2 to start rotating again. Not to be.

Here, the triac T has a withstand current value of 40
A, The condenser 57b has a capacity of 15000 μF.

Next, a description will be given of a drilling method for drilling a hole in the concrete C to be excavated by using the drilling apparatus 1 having the above-described configuration. First, the direct motor 2 positioned above the column 4 is placed at a predetermined drilling position of the concrete C,
The base 3 is positioned so that the axes of the rotating shafts 11 coincide.
Is fixed to concrete C.

When the drilling apparatus main body 1a is installed on the concrete C, the main switch 53 of the power supply 1b is turned off.
On the N side, the current amount selection switch 54 is set according to the allowable current on the AC voltage supply side. The reset button 55b is pressed to apply a DC voltage to the brush 25 of the direct motor 2 to energize the coil of the rotor 17 (or the stator 18) to rotate the rotor 17 at a high speed of 4000 rpm or more, and to supply cooling water (not shown). Cooling water is fed from the device via a tube 24. The rotation speed at this time is controlled by turning a rotation speed adjustment knob 55a provided in the control unit 5a.

In this state, by lowering the direct motor 2 by the moving mechanism 5, the bit 1 of the core bit 13 connected to the tip of the rotating shaft 11 is moved.
5 is pressed against the surface of concrete C. In this way, an annular hole H is formed in the concrete C by the bit 15 rotating at a high speed. During the drilling operation, the bit 15 comes into contact with a hard reinforcing member such as a reinforcing bar for reinforcing the concrete C, and suddenly the direct motor 2
Is suppressed, the induced voltage is suddenly reduced and only the winding resistance is generated, causing an excessive current to flow. Therefore, the threshold is appropriately set, and when the current value detected by the current detector 59 exceeds the threshold, the triac control unit 58 immediately adjusts the firing angle of the gate current to adjust the phase control unit 56. Is set so that there is no output from. Thus, when the bit 15 comes into contact with a reinforcing member such as a reinforcing bar, the rotation of the direct motor 2 is immediately stopped, and the drilling operation is interrupted. Thus, when the interlock is activated and the drilling operation is interrupted, the drilling position is changed, and the operation is restarted without hitting the reinforcing bar. At this time, the reset button 55b is pressed to rotate the direct motor 2 again. After that, when the annular hole H is formed to a predetermined depth, the direct motor 2 is raised to open the hole H.
An anchor hole is formed by withdrawing the bit 15 from and removing the central core.

When the bit 15 is pulled out of the hole H by raising the direct motor 2, the core bit 13
When the core remains inside, the extruding rod 36 is extruded to the tip side.

As described above, according to the direct motor 2 having the above-described structure, by rotating the rotating shaft 11, the core bit 13 attached to the rotating shaft 11 is directly rotated without passing through a rotation transmitting mechanism such as a gear or a belt. Since the rotation is performed, torque transmission loss due to the rotation transmission mechanism can be eliminated, and the size and weight can be reduced. As a result, the handleability can be improved, and the deflection of the rotating shaft 11 can be minimized. Further, the generated noise can be reduced to a minimum.

The bit 1 at the tip of the core bit 13
Reference numeral 5 denotes an extremely high speed (40) by the direct motor 2 for directly applying a rotational force from the rotation shaft 11 to the core bit
(At least 00 rpm), and the peripheral speed of the bit 15 can be extremely increased. As described above, the rotation speed of the core bit 13 is set to the rotation speed obtained by the direct motor 2 and the rotation speed of the core bit 13 is increased by rotating the bit 15 at a high speed under a predetermined drilling speed. This means that the drilling depth, in other words, the depth of excavation of the bit 15 into the object to be excavated is reduced, and the resistance to excavation is reduced. The decrease in the resistance to the excavation exceeds the decrease in the torque generated by the direct motor 2, so that the drilling speed can be increased and the drilling time can be shortened. Thus, the perforation time can be reduced as compared with a case where the number of revolutions is reduced by using a gear or the like. By rotating the bit 15 at high speed in this manner, the tool load on the bit 15 is reduced, and even if the bit 15 has a blade thickness of less than 2 mm, the normal force, which is the force applied in the drilling direction, is reduced. hand,
The perforation time can be reduced.

If the bit 15 comes into contact with a reinforcing member such as a reinforcing bar buried in the concrete C during the drilling operation and the number of revolutions decreases or stops, the amount of current flowing through the direct motor 2 increases. Is detected, and when this value exceeds the threshold value, the application of the voltage to the direct motor 2 is immediately stopped by the motor drive voltage stopping means. In this way, the rotation of the bit 15 is completely stopped, so that the reinforcing body such as a reinforcing bar is prevented from being damaged.
It is possible to prevent an excessive current from flowing through the motor, causing the motor to generate heat, damaging the insulating film and short-circuiting the winding.

Further, since the bit 15 comes into contact with the reinforcing member to stop the rotation, the capacitor 57b connected in parallel to the direct motor 2 serves as a charge buffer even for an excessive current flowing instantaneously. It is possible to prevent an excessive current from flowing to the power supply 1b instantaneously. The triac T has a withstand current value of 40 A and is not destroyed by a surge current. Further, since the winding of the coil of the rotor 17 is coated with a heat-resistant resin such as polyimide, for example, even if an excessive current flows and heat is generated, the coating is easily removed, and a short circuit or the like occurs between the windings. Or not. Further, by using the triac T, not only the output control of the power supply 1b but also the power supply 1b can be performed.
b can be reduced in weight. Transformers required for high-output power supplies are usually large and heavy, but the use of power transistors allows the power supply 1b to be very small.

Further, the rotation speed adjusting knob 55a for adjusting the rotation speed of the direct motor 2 and the reset button 55b for restarting the drilling operation are provided on the drilling device main body 1a, so that the workability is improved. Can be.

The magnet provided on one of the rotor 17 and the stator 18 is a neodymium magnet.
Since it is a rare earth high density magnet of iron / boron system or samarium / cobalt system, the size of the rotor 17 or the stator 18 can be reduced, thereby further reducing the size and weight.

Further, since the rotary shaft 11 is press-fitted into the insertion hole 17a formed at the center of the rotor 17 and is directly fixed and integrated, the overall rigidity can be greatly improved. The hole can be formed by rotating the core bit 13 at a high speed, and the drilling speed can be greatly increased as compared with the conventional case. Thus, the drilling operation can be performed quickly, and the construction period of various construction operations including the drilling operation can be shortened.

Further, as compared with the case where an engine, a hydraulic motor or a geared motor for rotating a rotating shaft via a gear is used, noise can be greatly reduced (about 70 dB). , The labor required for maintenance work can be significantly reduced. In addition, since the through hole 11 a is formed at the center of the rotating shaft 11, the core bit 1
Cooling water can be supplied to the bit 15 that is the cutting edge of No. 3 to perform good excavation. Further, the adapter 12
By attaching and detaching the core bit 13, replacement with the core bit 13 having various diameters can be easily performed. Accordingly, maintenance such as replacement of the core bit 13 can be easily performed, workability can be improved, and since the core bit 13 is replaceable, the bit 15 having various blade thicknesses and shapes is provided. You can select and use one.

In the above embodiment, the motor drive voltage stopping means is configured so that the firing angle of the trigger current applied to the gate G of the triac T is adjusted so that no voltage is output to the rectifier 57. Of course, a configuration may be adopted in which a trigger current is not applied to G and a voltage is not output to the rectifier 57.

The output of the direct motor 2 is 80
Not only 0 W, but a higher output may be used,
It goes without saying that the diameter of the core bit 13 may be further increased in accordance with the generated torque to be obtained.

In the present embodiment, in addition to the above-described excellent configuration, the work consumed by friction or the like in the rotation transmission system such as a gear is reduced by the total work required when drilling a predetermined depth. The core bit 13 is directly attached to the rotating shaft 11 of the direct motor 2 without using a gear or the like so as not to increase the number of rotations. However, increasing the rotation speed of the core bit 13 can reduce the total work required for drilling a predetermined depth. As long as the work loss in the transmission system can be reduced, the core bit 13 is attached to the rotation shaft 11 of the direct motor 2 via a rotation transmission system such as a gear, and the core bit 13 is rotated at a rotation speed higher than the rotation speed of the direct motor 2. It is also possible to adopt a configuration in which the control is performed.

[0059]

The present invention has the following effects. As described above, according to the first aspect of the present invention, a motor that rotationally drives a tool for drilling an excavated object is a DC motor that is rotated by applying a DC voltage, and a motor power is supplied to the motor through a motor. The current detector for detection and the motor drive voltage stopping means for stopping the output of the DC voltage to the motor when the current value detected by the current detector exceeds a threshold value, so that the When the bit at the tip of the tool that drills the hole contacts the hard reinforcement in the excavated object, the current flowing through the motor increases, and the current detector detects that this current value exceeds the threshold and sends the current to the motor. Is stopped. In this way, when the bit abuts on the reinforcement, the rotation of the bit stops completely, preventing damage to the reinforcement, and causing excessive current to flow through the motor, causing the motor to generate heat, damaging the insulation film and winding. Can be prevented from being short-circuited.

According to the second aspect of the present invention, a part of the phase of the AC voltage on the input side is periodically output by adjusting the firing angle of the trigger current given to the gate of the triac by the motor power supply. Since the motor drive voltage stopping means is configured to adjust the firing angle and stop outputting the voltage from the phase control unit when the current value exceeds the threshold value, When the bit at the tool tip for drilling an object comes into contact with the hard reinforcement in the excavated object, the current flowing to the motor increases, and control is performed immediately when the current detector detects that this current value exceeds the threshold value. Motor drive voltage stopping means having a circuit sets the firing angle to 180 ° and stops applying voltage to the motor. In this way, when the bit abuts on the reinforcement, the rotation of the bit completely stops, preventing damage to the reinforcement, and causing excessive current to flow through the motor, causing the motor to generate heat, damaging the insulation film and winding. A short circuit or the like can be prevented.

According to the third aspect of the present invention, since the rectifier of the motor power supply has a capacitor connected in parallel with the motor, if the capacity of the capacitor is increased, the voltage applied to the motor is increased. Not only is it effective in removing voltage ripples and stabilizing the voltage, but also as a charge buffer that supplies a surge current that flows instantaneously when the bit stops in contact with the reinforcement. The capacitor serves to prevent an excessive current from flowing to the motor power supply instantaneously.

According to the fourth aspect of the present invention, the rotary shaft is penetrated and provided integrally with the rotor constituting the motor, and a tool is attached to the tip of the rotary shaft. The torque can be directly used for excavation without being lost due to friction of the rotation transmission mechanism. Also,
Both weight and noise can be reduced. Furthermore, since the bit can be rotated at a high speed, the depth of the bit excavated into the excavated object is reduced, the resistance to excavation is reduced, the drilling speed is increased, and the drilling time is shortened.

According to the fifth aspect of the present invention, since the tool having the bit at the tip and the rotary shaft are provided in a cylindrical shape and are configured to communicate with each other in the axial direction, the tool can be moved from the rotary shaft to the tool. Not only can water be passed through for wet drilling toward the tip bit, but also the core core remaining in the concrete after drilling concrete can be pulled out through the rotating shaft or inserted with an extruding rod to extrude the core core You can also. Also, various configurations for cooling can be provided in the rotating shaft. For example, cooling may be performed by passing cooling water, providing a fan for air cooling, passing liquid nitrogen or dry ice, or adiabatically expanding a compressed gas. In particular, since the rotating shaft is directly attached to the rotor of the motor and provided integrally with the rotor, the heat conductivity to the motor is good, and the motor can be efficiently cooled.

According to the sixth aspect of the present invention, the triac has a withstand current value of at least 40 A and the capacitor has at least a capacity of 15000 μF. Even when an excessive current flows to the motor, the capacitor supplies a surge current even when an excessive current flows to the motor, so that an excessive current does not instantaneously flow to the motor power supply. Further, the triac also has a sufficient current resistance, and can be prevented from being broken.

According to the seventh aspect of the present invention, since the winding inside the motor is covered with a heat-resistant resin,
The windings have sufficient heat resistance even if the bit abuts against a hard excavated object and the motor speed drops, and even if a large amount of current determined only by the winding resistance flows through the motor as the induced voltage decreases and Joule heat is generated, Since it has characteristics, it is possible to prevent a short circuit from occurring between the windings.

According to the eighth aspect of the present invention, the tool and the motor are provided separately from the motor power supply in the punching device main body, and the output of the DC voltage to the motor is stopped in the punching device main body. A reset button is provided to cancel the operation, so even if a current exceeding the threshold value flows to the motor and the voltage applied to the motor drops, after resetting the problem, the work can be resumed with the reset button at hand. Performance can be improved.

According to the ninth aspect of the present invention, a tool having a bit is mounted on a rotating shaft driven to rotate by a motor, and a DC voltage is applied to the motor from a motor power supply to rotate the motor. A drilling method in which a rotating bit is pressed against an object to be excavated to pierce the object, and an increase in the value of current flowing through the motor due to the contact of the bit with a reinforcing member embedded in the object to be excavated was detected and detected. Since the motor stops when the current value exceeds the threshold,
When the bit comes into contact with the reinforcing member, the output of the motor power supply stops, the rotation of the bit stops completely, preventing damage to the reinforcing member. It is possible to prevent the winding from being short-circuited due to breakage.

According to the tenth aspect of the present invention,
The rotating shaft is directly attached to the rotating rotor of the motor, and a tool having a bit at the tip is attached to the rotating shaft. The motor is rotated, and the rotating bit is pressed against the excavated object to pierce the excavated object. A drilling method, which increases the total number of rotations of a tool required to drill a predetermined depth, and reduces the depth of drilling per revolution of a bit to be drilled, thereby reducing resistance to drilling and reducing drilling. Since the required torque is reduced, the total work required for drilling a predetermined depth is reduced, and the drilling speed for drilling the excavated object is increased, the drilling time can be reduced.

According to the eleventh aspect of the present invention,
Since the motor is rotated at a high rotation speed so as to reduce the resistance to excavation, the drilling speed can be increased. When the bit comes into contact with the reinforcement, the output of the motor power supply is stopped, the rotation of the bit stops completely, preventing damage to the reinforcement and preventing excessive current from flowing through the motor, causing the motor to generate heat and insulation. It is possible to prevent the winding from being short-circuited due to breakage of the film.

According to the twelfth aspect of the present invention,
When an increase in the current value flowing to the motor due to the contact of the bit with the reinforcing body for reinforcing the excavated object buried in the excavated object is detected, and when the detected current value exceeds the threshold value,
Set the firing angle of the trigger current to the triac gate to 1
By adjusting the angle to 80 °, the output of the AC voltage on the input side is stopped so that the application of the DC voltage to the motor is stopped, so that the rotation of the bit is completely stopped, and the breakage of the reinforcing member is prevented. In this case, it is possible to prevent the motor from generating heat due to excessive current and causing the insulation film to be damaged and the winding to be short-circuited.

According to the thirteenth aspect of the present invention,
Since the triac has a withstand current value of at least 40 A and the capacitor has a capacity of at least 15000 μF, the bit abuts against a reinforcing member such as a reinforcing bar in concrete during drilling and stops, and an excessive current Even if the current flows, the capacity of the capacitor supplies a surge current, so that an excessive current does not flow instantaneously to the motor power supply.
Further, the triac also has a sufficient current resistance, and can be prevented from being broken.

[Brief description of the drawings]

FIG. 1 is a side view showing an example of an embodiment of a punching device of the present invention.

FIG. 2 is a side view showing the punching device main body of the punching device in a partially cutaway view.

FIG. 3 is a block diagram schematically showing connection of an electric circuit of the punching device of the present invention.

FIG. 4 is a cross-sectional view of a punching device for explaining the structure of a conventional punching device.

[Explanation of symbols]

 C: Concrete (excavated object) G: Gate H: Hole T: Triac T1: Input side T2: Output side 1: Drilling device 1a: Drilling device body 1b ... power supply (motor power supply) 2 ... direct motor (motor) 11 ... rotating shaft 13 ... core bit (tool) 15 ... bit 17 ... rotor 18 ... stator 55a ...・ Rotation speed adjustment knob 55b ・ ・ ・ Reset button 56 ・ ・ ・ Phase control unit 57 ・ ・ ・ Rectification unit

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) H02P 7/285 H02P 7/285 B 7/288 7/288 G (72) Inventor Shigeru Masaki Chiyoda-ku, Tokyo 1-5-1, Otemachi Mitsubishi Materials Co., Ltd. (72) Inventor Toshio Imaoka 681 Saedocho, Tsuzuki-ku, Yokohama-shi, Kanagawa Prefecture Japan Diamond Co., Ltd. (72) Inventor Kyushu Sato 5 Sotokanda, Chiyoda-ku, Tokyo -3-13 Onda Building 201 F-term (reference) HA16 HB01 HD04 KK02 MM02 PP05

Claims (13)

[Claims] 1. A drilling machine comprising: a tool having a bit for drilling an excavated object at a tip thereof; a motor for rotating and driving the tool; and a motor power supply for applying a voltage to the motor. Is a DC motor that rotates when a DC voltage is applied, the motor power supply includes a current detector that detects a current flowing through the motor, and a current value detected by the current detector that exceeds a threshold value. And a motor drive voltage stopping means for stopping the output of the DC voltage to the motor. 2. The drilling device according to claim 1, wherein the motor power supply adjusts a firing angle of a trigger current to be applied to a gate of the triac to periodically cycle a part of the phase of the AC voltage on the input side. And a rectifying unit that rectifies a voltage on the output side of the phase control unit so as to apply the DC voltage to the motor and smoothes a voltage pulsation, the motor drive voltage stopping unit. Is configured to adjust the firing angle when the current value exceeds a threshold value to stop outputting a voltage to the rectifier. 3. The perforating apparatus according to claim 2, wherein the rectifying unit has a condenser connected in parallel with the motor. 4. The drilling device according to claim 1, wherein the motor has a cylindrical shape in which a rotating shaft to which the tool is attached is penetrated at an end thereof and is integrally provided. And a cylindrical stator provided on an outer peripheral surface of the rotor. 5. The drilling device according to claim 4, wherein the tool having the bit at its tip and the rotating shaft are:
A boring device, wherein each of the boring devices is provided in a cylindrical shape, and the tool is attached to the rotating shaft so as to communicate with each other in the axial direction. 6. The drilling device according to claim 3, wherein the triac has a withstand current value of at least 40 A, and the capacitor has a capacitance of at least 15000 μF.
A perforation device characterized by having: 7. The drilling device according to claim 1, wherein a winding inside the motor is covered with a heat-resistant resin. 8. The drilling device according to claim 1, wherein the tool having the bit and the motor are provided separately from the motor power source in the drilling device main body. A punching device, wherein the punching device main body is provided with a reset button for canceling stop of output of the DC voltage to the motor. 9. A tool having a bit is attached to a rotating shaft that is rotated and driven by a motor, a DC voltage is applied to the motor from a motor power supply to rotate the motor, and the rotating bit is attached to an excavated object. A drilling method for punching the excavated object by pressing, wherein an increase in a current value flowing through the motor due to the bit contacting a reinforcing body for reinforcing the excavated object embedded in the excavated object. Wherein the motor is stopped when the detected current value exceeds a threshold value. 10. A rotating shaft is directly attached to a rotating rotor of a motor, and a tool having a bit at a tip is attached to the rotating shaft to rotate the motor and to push the rotating bit against an object to be excavated. A drilling method for piercing said excavated object, wherein the total number of rotations of said tool required for drilling a predetermined depth is increased, and a depth of excavation per revolution of said bit to said excavated object is increased. Reducing the resistance to excavation and the torque required for excavation by reducing the depth, reducing the total work required for drilling the predetermined depth, and increasing the drilling speed for drilling the excavated object. Drilling method. 11. The drilling method according to claim 10, wherein a value of a current value flowing through the motor when the bit comes into contact with a reinforcing member that reinforces the object to be excavated embedded in the object to be excavated. A perforation method comprising detecting an increase and stopping the motor when a detected current value exceeds a threshold value. 12. The drilling method according to claim 9, wherein the bit comes into contact with a reinforcing member for reinforcing the excavated object buried in the excavated object. The output of the AC voltage on the input side is stopped by adjusting the firing angle of the trigger current given to the triac gate when the increase in the current value flowing through the motor is detected and the detected current value exceeds the threshold value. The application of the DC voltage to the motor is stopped. 13. The drilling method according to claim 12, wherein the triac has a withstand current value of at least 40 A, and the capacitor has a capacity of at least 15000 μF.
A perforation method characterized by having: